Quick Start Guide Orion 920Aplus pH/ISE Meter
Calibration of Ion-Selective Electrodes (ISE) with
Two Standards
1. Verify selected input is currently in use. If input 1 to be used, the prompt line
should indicate “1-”. If input not correct, press 2nd then channel repeatedly
until selected input is displayed.
2. Select electrode ID for the electrode in use. For example to select Fluoride
(F - ): press 2nd then electrode ID. Enter 3then press yes. For other
choices press 2nd then electrode ID, press no to scroll through other ISE
choice. Enter number of selection and then press yes.
3. Select “CONCENTRATION” mode by pressing mode until “CON” is
displayed on main display.
4. Place electrode(s) into first standard and stir moderately.
5. Press calibrate. The date and time of the last calibration is displayed.
6. Press 2then yes to select 2 standard calibration.
7. When “READY ENTER VALUE” is displayed on prompt line, indicating
electrode is stable, enter value of standard and press yes. The standard value
is entered, stored and the meter display freezes for three seconds. The meter
automatically switches to standard 2.
8. Remove electrode(s) from first standard. Rinse with deionized water.
9. Place electrode(s) into second standard.
10. When “READY ENTER VALUE” is displayed on the prompt line, indicating
electrode is stable, enter value of standard and press yes.
11. The electrode slope is calculated and then actual value is displayed for
5 seconds. Meter then automatically proceeds to MEASURE mode.
12. Remove electrode(s) from standard. Rinse with deionized water. Place
electrode(s) into sample. When “RDY” is displayed, record the sample results.
pH Autocalibration with Two Buffers
1. Verify selected input is currently in use. If input 1 to be used, prompt line
should indicate “1-”. If input not correct, press 2nd then channel repeatedly
until selected channel is displayed.
2. Select electrode ID for the electrode in use. If pH electrode to be used the
prompt line should read “1-pH”. If pH not displayed then press 2nd then
electrode ID. Enter 1then press yes.
3. Select pH mode, by pressing mode until pH displayed on main display.
4. Place electrode(s) into pH 7 buffer and stir moderately.
5. Press calibrate. The date and time of the last calibration is displayed.
6. Press 2then yes to select 2 buffer calibration.
7. When “RDY” is displayed on prompt line, indicating electrode stability, press
yes. The buffer value is entered, stored and meter display freezes for three
seconds. The meter automatically switches to buffer 2.
8. Remove electrode(s) from first buffer. Rinse with deionized water.
9. Place electrode(s) into second buffer.
10. When “RDY” is displayed on prompt line, press yes.
11. The electrode slope is calculated and then actual value (in percent) is
displayed for five seconds. Meter will then automatically proceed to the
MEASURE mode.
12. Remove electrode(s) from buffer. Rinse with deionized water. Place
electrode(s) into sample. When “RDY” is displayed, record the
sample results.
233945-001 Rev. C